DE1163541B - Process for preparing linear polyamides of high viscosity from ª‰-lactams which are unsubstituted on the nitrogen - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Boarding school Class: C 08 g

German class: 39 c -10

Number: 1163 541

File number: F 33274IV d / 39 c

Filing date: February 24, 1961

Opened on: February 20, 1964

It has already been suggested that lactams unsubstituted on nitrogen should be considered to be catalytic Polymerize exposure to alkali lactamates to form linear polyamides. It was also suggested that to accelerate the polymerization by adding N-acyllactams (activators).

It has now been found that linear polyamides of high relative viscosity can be obtained from nitrogen unsubstituted ^ -lactams by alkaline catalytic ^ polymerization in the presence of activators obtained when the polymerization is carried out in the presence of N-acyl or N-sulfonyl compounds of dicarboxylic acid diamides, which no longer have a hydrogen atom on both nitrogen atoms wear and / or in the presence of N-sulfonyl compounds from lactams and disulfonic acids as activators.

_{This finding was surprising since such an ao} effect has not been observed in the alkaline polymerization of pyrrolidone in the presence of bifunctional activators (see German Auslegeschrift 1 025 140, Examples 4 and 5).

Process for the production of linear polyamides high viscosity from ^ -lactams unsubstituted on nitrogen

Applicant:

Farbwerke Hoechst Aktiengesellschaft formerly Master Lucius & Brüning, Frankfurt / M., Brüningstr. 45

Named as inventor:

Dr. Erwin Schmidt,

Dr. Claus Beermann,

Frankfurt / M.-Unterh'ederbach, Dr. Karl Börner, Bobingen via Augsburg

As bifunctional activators are such. B. Oxalyldipyrrolidone, adipinyl-bis- (ß-methyl-ß-butyrolactam), a connection of the structure

O O

• Il Il

CH ₃ -CNC-CH ₂ -O CH ₃ CH ₃

CH ₃

1,3-benzene-disulfonyl-dipyrrolidone or the reaction products of lactams or acyl or sulfonylamino compounds, which still have a hydrogen atom on the nitrogen, with diisocyanates or bischloroformic acid esters of glycols.

One can use the bifunctional acyl compound in question also only generate in the polymerization approach by making this bifunctional acylating or sulfonating agents, such as the chlorides or anhydrides of dicarboxylic or disulfonic acids, as well as diisocyanates or bischloroformic acid esters of glycols.

The necessary amount of activator results from the activity of the bifunctional acyl compound used and from the tendency of the ^ -lactam used to polymerize. Preference is given to amounts of 10 ^-6 to 2 x 10 ^"3 moles of activator per Mcnomereneinheit use. The polymerization is carried out under the mildest possible conditions, wherein the reaction temperature is kept below 6O ⁰ C. It is advantageous to operate at temperatures of -15 to +30 ⁰ C.

The alkali or alkaline earth compounds of very weak are known to be suitable as catalysts. acidic substances such as lactams, carboxylic acid or sulfonic acid amides, acetylacetone or Malonic esters and alcohols. Also the hydrides or amides of the alkali and alkaline earth metals, organometallic compounds such as phenyl sodium and caustic alkali or alkali metal can find use for this.

The amount of the alkali compound used as a catalyst can vary within wide limits, without a noticeable change in viscosity of the polymer obtained. Appropriate 0.001 to 0.1 mol, preferably 0.001 to 0.06 mol, of alkali metal compound are used per monomer unit to.

Solvents are used in the polymerization under the conditions according to the invention. Solvents which have proven to be suitable are not only the monomer and the activator solve, but also have a swelling effect on the precipitating polymer. Such solvents are

409 509/468

ζ. B. dimethyl sulfoxide, N-methylpyrrolidone, dimethylformamide, Phosphoric acid tris-dimethylamide and o-dichlorobenzene.

To achieve a particularly high viscosity, it is advantageous in the claimed method that Monomers as well as the solvent used largely from traces of moisture and chain-breaking ones To get rid of impurities of a weakly acidic nature. Removal of moisture as well as the contamination takes place by distillation with the addition of a water immiscible Solvent or by blowing out with dried inert gas and by distillation under Addition of caustic alkali, the alkali salts of very weakly acidic compounds, such as alkali lactamates, the alkali compounds of acetylacetone or malonic ester or by adding organometallic Compounds such as Grignard compounds, phenyl sodium or alkyl aluminum compounds. The hydrides of alkali or alkaline earth metals are also suitable for this purpose.

example 1

First, 24 g / S-methyl-β-butyrolactam are dissolved in 85 cm ^{3 of} technical-grade dimethyl sulfoxide and 25 cm ^{3 of} the solvent are distilled off in vacuo. The solution is then cooled to 20 ^° C. in a bath.

With the exclusion of moisture and oxygen, 1 g of pyrrolidone-potassium and, according to the invention, 0.0022 g of oxalyldipyrrolidone are added. After a reaction time of 1 hour at 20 ^° C., the reaction mixture is introduced into 200 cm ^{3 of} acetone with the addition of a little glacial acetic acid and stirred with 500 cm ^{3 of} water, filtered off with suction and dried.

The yield of polymer is 21 g. The relative viscosity of the product is 9.0, measured on a solution of 0.1 g of substance in 10 cm ^{3 of} concentrated sulfuric acid.

If, under otherwise identical conditions, 0.0025 g of acetylpyrrolidone is used instead of If oxalyldipyrrolidone is used as an activator, 21 g of polymer having a relative viscosity of 7.5 are obtained.

Example 2

45

a) Purification of the monomer and the solvent: A mixture of 2 kg / I-methyl - /? - butyrolactam is heated and 500 g of xylene in an 80 cm long silver jacketed column with exclusion of moisture and oxygen for 4 hours under reflux at a vacuum of 15 torr. Then fractionation is carried out over the top of the column. That so Purified lactam has a residual moisture of O, OO4o / o.

5 kg of technical dimethyl sulfoxide are stored over potassium hydroxide for 48 hours, with one purple discoloration occurs. It is filtered and heated in an 80 cm long silver jacketed column for 6 hours in vacuo under reflux, while maintaining the vacuum through a not too narrow The capillary introduces a stream of dried nitrogen into the liquid.

The solvent is then distilled off over the top of the column. The so cleaned Dimethyl sulfoxide has a residual moisture content of 0.008% and shows after the addition of Pyrrolidone-Potassium no discoloration even after several minutes. One can use the dimethyl sulfoxide also clean in such a way that the technical product in excess, based on its water content, Phenylmagnesium bromide is added and then distilled.

b) From a mixture of 300 cm ^{3 of} methyl / 3-butyrolactam and 2150 cm ^{3 of} dimethyl sulfoxide, both of which have been purified in the manner described, 720 cm ^{2 of} the solvent are distilled off under vacuum to remove residual amounts of moisture.

In an atmosphere of dried nitrogen, 12 g of pyrrolidone potassium and, according to the invention, 0.027 g of oxalyldipyrrolidone are added to the residue. After 1 ^ permanent polymerization at 20 ^° C., the batch is introduced into 31 ^{% acetone with the addition of 10 cm 3 of} glacial acetic acid, stirred with 3 l of water, filtered off with suction and dried.

Yield: 246 g of polymer with a relative viscosity of 18.4, measured on a solution of 0.1 g of substance in 10 cm ^{3 of} concentrated sulfuric acid at 20 ^° C.

Polymerization is carried out under otherwise identical conditions using 0.03 g of acetylpyrrolidone Instead of oxalyl-dipyrrolidone, 234 g of a polymer having a relative viscosity of 11.8 are obtained.

Example 3

The procedure is as in Example 2 using 0.030 g of adipinyl bis (/ 3-methyl-j3-butyrolactam) according to the invention instead of oxalyldipyrrolidone. Yield: 240 g of polymer, relative viscosity 13.5.

Example 4

From a mixture of 95 g / S-methyl-ß-butyrolactam, 5 g (S-neopentyl-ß-butyrolactam and 700 cm ^{3 of} dimethyl sulfoxide, the components of which were purified as in Example 2, 220 cm ^{3 are} distilled off to remove residual amounts of moisture .

After adding 4 g of pyrrolidone-potassium and, according to the invention, 0.005 g of oxalyl-dipyrrolidone, polymerization is carried out for 2 ¹ I for ₂ hours at 20 to 25 ° C., stirred with acetone with the addition of glacial acetic acid, taken up in water, filtered off with suction and dried.

Yield: 73 g of polymer with a relative viscosity of 14.1.

Claims (2)

Patent claims: 1. Process for the production of linear polyamides of high relative viscosity from nitrogen unsubstituted / 9-lactams by alkaline catalytic polymerization in the presence of Activators, characterized in that the polymerization is carried out in the presence of N-acyl or N-sulfonyl compounds of dicarboxylic acid diamides, which no longer carry a hydrogen atom on both nitrogen atoms, and / or in the presence of N-sulfonyl compounds from lactams and disulfonic acids as activators. 2. The method according to claim 1, characterized in that the bifunctional N-acyl or N-sulfonyl ^{compounds are used in amounts of 10 ~ 6} to 2 · 6 " ³ mol per monomer unit. 409 509/468 2.64 θ Bundesdruckerd Berlin